The Frustration of San Francisco's Mass-Transit Riders, Visualized

If one were to somehow take a mental-health reading of San Francisco's public-transit riders at 6:30 p.m. on a Monday, it might look something like this:

Large knots of people are angry about overcrowded vehicles along Haight Street and Divisadero at Castro, perhaps due to swarms of techies disembarking from Google and Apple shuttles. Folks in Lower Nob Hill are P.O.ed about schedule delays. Traffic jams are ticking off riders in the Crocker-Amazon neighborhood, and over on Balboa Street in the Richmond District, people are seething over a perfect storm of bad service involving slow, late vehicles packed tighter than cans of Italian olives.

That remarkably detailed assessment of the city's transit woes comes from the "Frustration Index," a web app that visualizes service satisfaction for mass transit in San Francisco, Geneva and Zurich based on three criteria: capacity, delays and speed. (Try it out here, but be warned that it might make your browser crawl slower than a bus with two flats.) Based on ridership information from one day in October 2012, the app is meant as a "way to compare happiness across the three cities," the programmers say. The Index recently won second prize in the Urban Data Challenge, a Bay Area-centered competition to improve transit performance through creative uses of government data.

To build their map of commuter acrimony, the Index team consulted transportation planners in San Francisco and Switzerland. The model uses formulas that might look like witchcraft to non-mathematicians, such as this calculation for capacity: "Pnt = ∑(Bx-Ex) for x starting at 1 until n (where 1 is the first stop of the trip)." The way it works is you type in a time of day and it will spit out grades from A to F for specific frustrations, as well as display the ridership's presumed state of mind as amusing weather icons. "Excellent" service prompts a sunny sky, while "worst-quality" situations get a lightning-throwing thundercloud. It's color-coded, as well:

In the future, the programmers hope to create a mobile-phone app that would allow commuters to choose the best route for their individual tastes. Riders would give the app some information on what they really hated – waiting for a bus but maybe not crowded buses, for instance – and the program would make a "dream route" that minimized their pet peeves. The programming team also at one point dreamed of testing a sister "Happiness Index," although that probably won't get made. "We wanted to turn it positive too!" they say. "However, due to the scope of this project and visual clarity, we decided to only consider frustration factors."

Take the Index for a joyride through the day and you'll discover drastically different service levels around the city. Here's the relative calm of Monday at 11:30 p.m.: